All OpenAI models

GPT-5.1-Codex-Max

OpenAI · released December 2025

GPT-5.1-Codex-Max is a OpenAI model with a 400K token context window — about 570 pages of text. It reads Text and Images and replies in Text. It can show its reasoning before it answers.

$1.44

input / 1M tokens

$11.50

output / 1M tokens

400K

context — about 570 pages

1.6¢

a client proposal

Pricing

Input
$1.44 per million tokens
Output
$11.50 per million tokens
Cached input
$0.144 per million tokens
Web search
1.1¢ per search

Billed from your Alyph wallet. Prices can change when the provider changes theirs — last checked August 9, 2026.

The numbers

Provider
OpenAI
Released
December 2025 (2025-12-04)
Context window
400K tokens — about 570 pages
Max output
128K tokens per reply
Input
Text and Images
Output
Text
Reasoning
Shows its thinking before answering

Cost vs Token Amount

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80% Input20% Output
free$1.72$3.450 tokens250k500k750k1000k
GPT-5.1-Codex-Max

Adjust the ratio slider to change how output tokens influence the final price for equivalent workloads.

What a task costs

2K tokens in · 500 tokens out.

GPT-5.1-Codex-Max

OpenAI

0.86¢

for this task

33% input · 67% output

Full pricing →

Your $5 welcome credit covers about 579 of these.

Compare GPT-5.1-Codex-Max

Closest in price on a typical task:

GPT-5.1-Codex-Max vs Gemini 2.5 Pro →GPT-5.1-Codex-Max vs Gemini 2.5 Pro Preview 05-06 →GPT-5.1-Codex-Max vs Gemini 2.5 Pro Preview 06-05 →GPT-5.1-Codex-Max vs GPT-5 →Any other combination →

Questions, answered

How much does GPT-5.1-Codex-Max cost on Alyph?

GPT-5.1-Codex-Max costs $1.44 per million input tokens and $11.50 per million output tokens on Alyph. A typical task — 5K tokens in, 800 out — works out to about 1.6¢. Billed from your Alyph wallet, with hard spending limits. Prices can change when the provider changes theirs; this page was last checked on August 9, 2026.

What is GPT-5.1-Codex-Max's context window?

400K tokens — about 570 pages. Replies can be up to 128K tokens long.

Can GPT-5.1-Codex-Max read images and files?

GPT-5.1-Codex-Max reads Text and Images. Drop a file onto the canvas and it becomes part of the context — the only limit is the context window.

Does GPT-5.1-Codex-Max show its reasoning?

Yes. GPT-5.1-Codex-Max can expose its thinking before the final answer, so you can watch how it got there.

Test GPT-5.1-Codex-Max against Gemini 2.5 Pro

One prompt, both models at the same time, the better answer wins. Free to start, with $5 of credit.

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